Beginning about, or at least gaining popularity, in the early 1950's, driving enthusiasts, particularly younger driving enthusiasts, removed the factory muffler and installed “glass packs” or other aftermarket mufflers that enhanced the sound of the exhausts, particularly when accelerating from a stop or a low speed. Many didn't stop there, but went further to split the manifold(s) or to install headers to be able to install a second exhaust pipe, glass pack and tail pipe producing true dual exhaust, better known then as “a set of pipes”. Some of those sets of pipes had a very sweet sound, particularly to anyone who happened to be in the vicinity when the vehicle was accelerating, a sound that is rarely heard today. The closest thing to it heard today is a Harley Davidson®, but its sound is much harsher and louder. Nevertheless, one of Harley Davidson's® top selling features is it's exhaust sound.
Also, in the 1950's and 1960's it became popular to add sets of louvers to the hood, not only for looks, but also to allow the engine sounds to be better heard by the people in the vicinity, including the driver and passengers, particularly at high RPM's. At that time, vehicle air conditioning was rare and the front windows were rolled down during driving much of the time allowing the sounds of the vehicle to be better heard.
These sound enhancing features increased the sensual thrills and fun of driving, but usually sounded better to those outside the vehicle on the sidewalks, etc. than they did to the driver. Due to the Doppler effect and the interference of the passenger compartment, the driver never experienced the full potential of the enhanced sounds. This was before the time of air conditioners in the car and driving enthusiasts drove with the windows down even when the temperature didn't favor that, just to better experience the sounds of the pipes and the engine. Alas, now with air conditioning, terrible wind noise with the windows down and even better sound deadening in the passenger compartment, one can barely hear the engine and usually not the exhaust.
Many cars today appear to have dual exhaust, but most are not true dual exhausts, just two tailpipes coming from a common catalytic converter or muffler. Also, most mufflers do a good job of hiding the exhaust sound and do not give the enthusiasts what they want to hear. A few auto manufacturers have modified their mufflers to provide a deeper, throaty and louder sound, but still the normally closed and well insulated passenger compartment prevents the full excitement of the improvement. Maybe because the driver can no longer really enjoy his pipes, few bother to replace their factory mufflers with better sounding ones, and few such options exist today for that reason. Almost no one goes to the expense of adding louvers to the hood.
Convertibles and roadsters have enjoyed a real come-back in recent years, probably because the driver, and passenger, can better experience the thrill of the sounds of performance. But alas, even they loose some to much of the potential thrills due to wind noise and Doppler effect, and rainy or cold weather. These are very old problems as most, maybe all, auto enthusiasts will agree. Many years ago a company named Ronco® marketed a product called Mr. Microphone® that contained a microphone and allowed a person or persons to broadcast on a predetermined FM frequency their voice(s) to the auto's FM radio when it was tuned to the same frequency, but while people had fun with this device, it did not solve or reduce the problems described above. Even today, Volkswagon® offers a device that permits an electric Guitar, etc. to be played through the auto's audio system, but this device also does not solve or reduce the problems described above.
Automakers are in a highly competitive performance environment. They have been steadily increasing the horsepower of their high-performance vehicles, hoping this will have a halo effect on the entire brand. For instance, Dodge advertises its “Hemi” engine. BMW features its “M” series. Nissan/Infiniti has added an additional exhaust sound to their sports models, with a sound-effect that is prominent in their advertising. These are just a few examples of many that try to differentiate via enhanced performance or the impression or reputation thereof.